arXiv subjects

Haiyan Sun

Publications and source records attributed to Haiyan Sun.

5 recordsLinked to original sources

arXiv2026

Revisiting the Perception-Distortion Trade-off with Spatial-Semantic Guided Super-Resolution

Image super-resolution (SR) aims to reconstruct high resolution images with both high perceptual quality and low distortion, but is fundamentally limited by the perception-distortion trade-off. GAN-based SR methods reduce distortion but still struggle with realistic fine-grained textures, whereas diffusion-based approaches synthesize rich details but often deviate from the input, hallucinating structures and degrading fidelity. This tension raises a key challenge: how to exploit the powerful generative priors of diffusion models without sacrificing fidelity. To address this, we propose SpaSemSR, a spatial-semantic guided diffusion framework with two complementary guidances. First, spatial-grounded textual guidance integrates object-level spatial cues with semantic prompts, aligning textual and visual structures to reduce distortion. Second, semantic-enhanced visual guidance with a multi-encoder design and semantic degradation constraints unifies multimodal semantic priors, improving perceptual realism under severe degradations. These complementary guidances are adaptively fused into the diffusion process via spatial-semantic attention, suppressing distortion and hallucination while retaining the strengths of diffusion models. Extensive experiments on multiple benchmarks show that SpaSemSR achieves a superior perception-distortion balance, producing both realistic and faithful restorations.

cs.CV↗

arXiv2024

Enhanced Hydrogen Evolution Catalysis of Pentlandite due to the Increases in Coordination Number and Sulfur Vacancy during Cubic-Hexagonal Phase Transition

The search for new phases is an important direction in materials science. The phase transition of sulfides results in significant changes in catalytic performance, such as MoS2 and WS2. Cubic pentlandite [cPn, (Fe, Ni)9S8] can be a functional material in batteries, solar cells, and catalytic fields. However, no report about the material properties of other phases of pentlandite exists. In this study, the unit-cell parameters of a new phase of pentlandite, sulfur-vacancy enriched hexagonal pentlandite (hPn), and the phase boundary between cPn and hPn were determined for the first time. Compared to cPn, the hPn shows a high coordination number, more sulfur vacancies, and high conductivity, which result in significantly higher hydrogen evolution performance of hPn than that of cPn and make the non-nano rock catalyst hPn superior to other most known nanosulfide catalysts. The increase of sulfur vacancies during phase transition provides a new approach to designing functional materials.

physics.chem-ph↗

arXiv2018

Exfoliation of Few-Layer Black Phosphorus in Low-Boiling-Point Solvents and Its Application in Li-Ion Batteries

The liquid-phase exfoliation (LPE) of black phosphorus (BP) is a strategic route for the large-scale production of phosphorene and few-layer BP (FL-BP) flakes. The exploitation of this exfoliated material in cutting-edge technologies, e.g., in flexible electronics and energy storage, is however limited by the fact that the LPE of BP is usually carried out at a high boiling point and in toxic solvents. In fact, the solvent residual is detrimental to device performance in real applications; thus, complete solvent removal is critical. Here, we tackle these issues by exfoliating BP in different low boiling-point solvents. Among these solvents, we find that acetone also provides a high concentration of exfoliated BP, leading to the production of FL-BP flakes with an average lateral size and thickness of c.a. 30 and 7 nm, respectively. The use of acetone to produce less defective few-layer BP flakes (FL-BPacetone) from bulk crystals is a straightforward process which enables the rapid preparation of homogeneous thin films thanks to the fast solvent evaporation. The ratio of edge to bulk atoms for the BP flakes here produced, combined with the use of low-boiling-point solvents for the exfoliation process suggests that these thin films are promising anodes for lithium-ion batteries. To this end, we tested Li-ion half cells with FL-BPacetone anodes achieving a reversible specific capacity of 480 mAh/g at a current density of 100 mA/g, over 100 charge/discharge cycles. Moreover, a reversible specific capacity of 345 mAh/g is achieved for the FL-BPacetone-based anode at a high current density (i.e., 1 A/g). These findings indicate that the FL-BPacetone-based battery is promising with regards to the design of fast charge/discharge devices. Overall, the presented process is a step forward toward the fabrication of phosphorene-based devices.

cond-mat.mtrl-sci↗

arXiv2018

High-yield production of 2D crystals by wet-jet milling

Efficient and scalable production of two-dimensional (2D) materials is required to overcome technological hurdles towards the creation of a 2D-materials-based industry. Here, we present a novel approach developed for the exfoliation of layered crystals, i.e., graphite, hexagonal boron nitride and transition metal dichalcogenides. The process is based on high-pressure wet-jet-milling (WJM), resulting in 2 L/hr production of 10 g/L of single- and few-layer 2D crystal flakes in dispersion making the scaling-up more affordable. The WJM process enables the production of defect-free and high-quality 2D-crystal dispersions on a large scale, opening the way for the full exploitation in different commercial applications, e.g., anodes active material in lithium ion batteries, reinforcement in polymer-graphene composites, and transparent conductors as we demonstrate in this report.

cond-mat.mtrl-sci↗

arXiv2013

Cryptanalysis and improvement of two certificateless three-party authenticated key agreement protocols

Recently, two certificateless three-party authenticated key agreement protocols were proposed, and both protocols were claimed they can meet the desirable security properties including forward security, key compromise impersonation resistance and so on. Through cryptanalysis, we show that one neither meets forward security and key compromise impersonation resistance nor resists an attack by an adversary who knows all users' secret values, and the other cannot resist key compromise impersonation attack. Finally, we propose improved protocols to make up two original protocols' security weaknesses, respectively. Further security analysis shows that our improved protocols can remove such security weaknesses.

cs.CR↗